The paper, written by Victor Gura, MD, of Cedars-Sinai Medical Center in Los Angeles and UCLA, and colleagues, reported certain technological advancements that allowed for the development of an artificial kidney that provides dialysis continuously 24 hours a day and allows patients to remain untethered from a dialysis machine. Studies have shown that more frequent dialysis may improve clinical outcomes.

Gura is chief medical and scientific officer of Xcorporeal, which is developing the current incarnation of the artificial kidney.

The device is worn as a belt, weighs about 10 pounds, and runs on two nine-volt batteries. Although lightweight, the artificial kidney would likely have to be slimmed down further. Here's a picture of Gura modeling a prototype in 2008.

If successful, such a device would come as a relief to patients on dialysis -- numbering about 400,000 in the U.S. -- allowing them to take their dogs for walks, go shopping, or do any of the other things they normally wouldn't be able to do as they spent hours and hours hooked up to the dialysis machine.

In a pilot study of eight patients with end-stage renal disease, published in The Lancetin 2007, an early version of the device resulted in a mean plasma urea clearance rate of 22.7 mL/min and a mean plasma creatinine clearance rate of 20.7 mL/min. The patients wore the device for up to eight hours and there were no adverse events. Six of the patients were able to walk around.

Gura started working on the project in 2001, but researchers have been trying to develop a wearable artificial kidney -- or WAK -- since the 1970s. Gura and his colleagues said these efforts have "failed due almost entirely to insurmountable technical problems."

Although the newest device has passed initial hurdles and addressed some of these difficulties, the researchers said, larger clinical trials are still needed to establish its long-term safety and efficacy.

The advancements detailed in this most recent paper are "but one additional step on a long road still ahead of us to bring about a much-needed change in the lives of this population," Gura said in a statement.

He and his colleagues did not include a cost analysis, but they said the cost of each device is expected to be less than that of current dialysis machines.

"We are painfully aware that our efforts to build a WAK would be useless if the implementation of its use in practice is not affordable," they said.